A Harlem lesbian who beat her lover’s toddler son to death in their roach-and-rodent-infested apartment because he’d soiled himself was sentenced to 15 years to life in prison yesterday.

In pleading guilty to murder last month, Carmen Molina, 35, admitted to beating the boy to death – but yesterday, in her presentencing “apology,” she laid blame on her ex, the boy’s mother, Zahira Matos, who’ll stand trial for murder in July.

Yovany Tellez – 23 months old and nicknamed “PaPo” – died in September 2004 with a pulverized liver, broken ribs and a broken leg, and covered in bruises and feces.

“He filled our life with happiness,” said the boy’s grandmother Maria Barosa, who is raising 23-year-old Matos’ surviving two daughters. “Now, I’m filled with sadness.”